docs: def exception_handler(self, callback):
          """
          Decorator to add an exception handler to the worker, e.g.::
  
              rq = RQ()
  
              @rq.exception_handler
              def my_custom_handler(job, *exc_info):
                  # do custom things here
                  ...
  
          """
          path = '.'.join([callback.__module__, callback.__name__])
          self._exception_handlers.append(path)
          return callback